Dirty Little Secret
by KlaineInsane
Summary: Kate Hummel is best friend's with Rachel Anderson. She also may or may not be hopelessly in love with Blaine Anderson, Rachel's father. And Blaine might actually have the same feelings in return. (not really good with summaries, I'm sorry! Reviews keep the chapters coming, please!) cisgirl!Kurt, older!Blaine, and future bdsm, dk!Klaine, little!Kurt, daddy!Blaine, etc.


"… I mean Finn is pretty hot, but I don't think he'd ever notice me." Rachel murmured. "Kate are you even listening to me?"

Kate was hummed in response as she nodded her head, doodling hearts onto her notebook. "Yeah, I heard you. " She applied. "You need to stop doubting yourself, Rachel Anderson. My step brother may be popular but I've seen his lingering stares at you."

Rachel couldn't help but smile at that, standing up from her bed. "That's true, he isn't very discreet," she lent her hand to help up her best friend. "How about we get my dad to make his famous Chicken Cordon Blu for lunch?"

"That sound's perfect, Rach. The best way to get out of these final exam studies." Kate complied, standing up as she followed Rachel into the kitchen, revealing her dad sitting at dining room table, a cup of coffee in one hand and that morning's paper in the other.

"Good afternoon, Mister Anderson. Catching up on the latest news?" Kate said with a small smile.

Blaine jumped a little at the sound of his daughter's best friend talking. "Rachel, Kate, good afternoon to you both." He grinned as he took a sip of his coffee. "Well of course I am, I do every day. Well, at least I try." He stood up and kissed the top of Rachel's head and headed over to the fridge. "What's on today's lunch menu?"

"Your famous Chicken Cordon Blu, it's one of Kate's favorite dishes of yours." Rachel commented, sitting down at the dining room table where her father once sat.

Kate looked at her friend in disbelief before letting a blush creep onto her cheeks. "Well it is one of your best dishes, Mister Anderson. Of course it's going to be my favorite." She corrected Rachel.

Rachel rolled her eyes and smiled. "Katie, you need to stop being like that. You've known me and my dad since we were in diapers," She clapped her hand onto Kate's shoulder. "And when was that? Like sixteen years ago?"

Blaine couldn't help but groan at that thought. Has it really been that long since his little girl and her best friend had met? "Stop making me feel old, would you? I can already start to see grey flecks in my hair and I'm only thirty five."

Kate giggled and watched as Blaine shook his head. "Oh come on, Mister Anderson. You have the latest Apple product's, you can't really say that you're old."

"Exactly, dad. Plus you're one of the best cooks around, including modern dishes." Rachel smirked and nudged her father. "It smells good already."

"It really does." Kate nodded in agreement, sniffing into the air followed by a moan. "My mouth is already watering."

What Kate just did shouldn't have affected Blaine the way that it just did. He cleared his throat with a grin on his face. "Well thank you, both of you." His eyes lingered on Kate before flicking them away as he flipped the chicken. "The restaurant is almost done with its reno, so that means we'll be able to open within a few weeks."

Rachel clapped her hands together in approval. "I can't wait," She said, helping her father plate the food. "Kate and I are going to be your very fist customers."

"I can't wait either." Kate murmured with a smile, grabbing the silver wear and set the table, as if she lived there with them. "This restaurant is going to be great business, I just know it."

Blaine just grinned and set down the plates before sitting down in his original spot. "Dig in, yeah?"

All three of them took a bit of the food and in unison made a noise of approval. Kate sighed contently and nodded. "Yes, this is definitely one of my favorite meals of yours, Mister Anderson."

Blaine couldn't help but blush at her comment. Yes, approval is always nice but just knowing Kate and her daughter likes almost all of his dishes made it complete. "You're just being biased, Kate Elizabeth. " He smirked. "And please, please stop calling me Mister Anderson, we've been over this. It makes me sound like my father."

Kate laughed in response, _god that laugh_ , Blaine thought, and just shook her head. "I wouldn't call myself biased, but maybe your number one supporter next to Rachel of course."

Rachel nodded with a smile pursing across her lips. "Both of us are your number one fans, Dad." She hummed. "Just accept the compliment."

Blaine sighed softly and smiled. "Thank you, I really need both of your supports." Blaine is a wonderful chef, but the support is also needed if he wants to make it in the restaurant business.

"Alright, well we better get back to studying, Katie. These exams aren't going to pass themselves." Rachel muttered, standing up and patting the crumbs off her clothes.

Kate smiled and nodded before gathering the plates together. "You go ahead, I'm going to stick back for a few and help Mist- I mean, your dad, clean up a bit." She flickered her eyes between the two as she brought all the plates to the sink.

Rachel just shrugged and nodded, disappearing out of the room.

"You didn't have to stay back and help you know," Blaine walked up to the sink and started to wash the dishes one by one. "I know how important these exams are to both of you."

She rolled her eyes before shrugging. "You did cook this amazing meal for us, I might as well help out with the mess that it made." Kate grabbed a dish and dried the plates that they had just dirtied. "Seriously though, thank you for everything, Bl-Blaine."

Blaine turned off the sink and nodded. "You're so welcome, Kate. Anything for you and Rachel." He dried off his hands with some loose paper towel and grinned down at Kate softly.

Kate couldn't help but melt into Blaine's eyes and smile, biting down onto her bottom lip. "I- I should go back to studying, thank you for lunch."

She walked out of the room after nodding once more at Blaine, letting her hips sway from side to side on purpose.

Blaine's eyes followed Kate's ass as each cheek bounced down with each walk in her very tight jean shorts. "Fuck.." He muttered quietly as soon as she was out of sight.

He had just finally noticed that Kate's body had finally fully developed, and the fact that he did actually noticed it was not good.

 _Not good at all._

* * *

The next couple weeks went by in a huge blur for Kate, both her exams was finally over with and Blaine's restaurant had opened up in time for Christmas break.

Kate shoved her books in her locker for the winter holidays just as the bell rings. It was finally time to go home and spend these next two weeks with family, friends, and lots of last minute holiday shopping.

"Nice glasses, Princess Leia." She heard a quite familiar feminine voice shout as she feels herself getting shoved into her now closed locker. "Did you get them on sale from the Harry Potter merchandise website?"

"Those are totally two different series of movies, Satan." Kate spat glaring at Santana and her group of gaudy cheerleaders.

Santana glared before smirking, holding up what looked like a Styrofoam cup filled with flavored ice which was now towering over Kate.

Then it happened, a rush of cold, wet ice went all over her body. She gasped, instantly putting her head down so she didn't give them the satisfaction of her now reddened eyes shedding a few tears.

"Not cool, Santana!" Kate heard Finn, her step brother, walk in between them. "That's my little sister and you better watch it."

"Whatever, Frankenteen." Santana snapped her fingers and had her posse follow her away down the hall.

"Oh my god," Rachel finally rushed over and wiped the slushy out of her best friends eyes. "Let's go get you cleaned up and then we can go back to my place for some banana splits, yeah?"

Finn cleared his throat as he turned around to face both of them. "Kate, god, I'm so sorry I didn't get here sooner."

Kate looked up and smiled weakly. "Finn, Rachel, I'm fine." She muffled. "Besides, it's not like this was the first time this has ever happened." She felt a heavy hand on her shoulder and leaned into it, looking up at Finn. "Thank you for sticking up for me, though."

"You're my little sister, Kate. Of course I'm going to help you out in any way that I can." Finn said, doing his signature half smile. "I'll see you at home later, okay? I'll tell Mom and Burt that you're going over to Rachel's house."

Rachel's eyes lit up at the recondition that Finn just gave her. "I'll bring her home in a few hours, Finn." She grinned and grabbed Kate's bag along with hers.

He just nodded and smiled before walking away, disappearing from their sight.

"Come on, my best friend is under there somewhere." Rachel nudged her. "Let's get you cleaned up, Katie."

Kate smiled contently and followed Rachel down to the girls restroom, getting her changed into her spare clothes and the slushy washed out of her hair.

They made it to the Anderson's house around three o'clock as per usual. They had made their banana splits and had gotten cozy on the living room couch with all of Rachel's pillows and blankets.

"Wicked, Singing in the rain, When Harry met Sally, or Moulin Rouge?" Rachel suggested as she went through her giant movie collection.

"Definitely When Harry met Sally, you know it's one of my favorites." Kate said in obviousness. "They get together in the end and it's so romantic."

"You know it's my dad's favorite, too." Rachel mention as she popped the DVD in the blue ray machine. "Both you and my dad are both hopeless romantics, its bittersweet."

Kate rolled her eyes and smirked. "Bittersweet? Say's the person who nearly orgasmed over the fact that my step brother nodded and smiled at you."

"I resent that!" Rachel cried with a laugh, sitting down next to Kate. "Is it weird that we've never had our first kisses and we're already seventeen."

Kate shrugged, looking over at Rachel. "I mean, I've thought about that yeah," She reached over and grabbed her best friend's hand." We're waiting for the right person and the right time."

Rachel nodded in a agreement, smiling softly. "Did I ever tell you how glad I am that you're my best friend?"

Kate laughed and grinned. "Well at least we're not going to end up like half the cheerleading squad," She took a bite of her ice cream. "A single knocked up teenage mother that is going nowhere in their lives."

"That's very true, it's already happened to Quinn Fabray."

To Kate's expectations, twenty minutes into the movie and Rachel had already fallen asleep. This always happens when they watch a movie together, but Kate didn't mind it all.

The front door started to wiggle, than a sound of unlocking happening before the door opens. In walks in Blaine, the look of pure exhaustion covering his stubbly face.

"Welcome home, Blaine." Kate whispered softly and waved to Rachel's father. "Be quiet, Rachel has fallen asleep."

Blaine was startled by the whispered voice, looking up and see both Kate and Rachel on his couch. "Thank you. How was school?"

Kate stood up from the couch and covered Rachel up with the Blankets before following Blaine into the kitchen. "School was the usual I guess." She said, setting up the coffee pot for Blaine like she normally does.

"Your damp hair tells me otherwise, Kate Elizabeth." Blaine acknowledged, gesturing to her hair. "Are you going to tell me what happened, or are you going to keep continuing to lie to me."

Kate sighed and looked up at Blaine. "Santana and her group of slutty cheerleaders may or may not have poured a forty two ounce slushy all over me." She pursed her lips. "But it doesn't even matter anyways, the school board won't do anything because I don't matter."

Blaine just shook his head and walked over to Kate, pushing a piece of hair out of her face and behind her ear. "Kate, don't you ever say that again." He advised sternly. "You matter, Kate. You matter to your family, your friends, Rachel, and especially me."

She melted into Blaine's hand on her cheek as if this felt normal for this behavior. "I know, Mister Anderson." Kate smiled softly and bit her lip as she looked up into Blaine's hazel eyes.

They stood like that for at least a moment until they hear a throat being cleared. _Oh god, Rachel is awake._ Kate jumped at least five feet away from Blaine, blushing brighter than ever.

"Dad, you're home." She smiled, trying to break the awkward silence. "How was work today? As busy as ever?"

Blaine nodded, his jaw tight with a smile. He poured himself a cup of coffee, taking a sip before speaking. "Of course, business is booming just like as you predicted."

Rachel smiled before yawning, rubbing her eyes tiredly. "We better get you home, Katie. It's almost dinner time and it's Friday night."

Kate cursed in her head for almost forgetting it was almost time for her and her father's tradition of Friday night dinners. "You're right, my dad would have killed me if I would have missed it."

"You are not driving when you are tired like this, Rachel. You get some rest and I'll drive Kate home." Blaine presumed. "I'll be back soon to start dinner."

Kate had gotten her stuff together before getting into Blaine's BMW and let him drive her home. The awkward silence in the car was just now starting to get on her nerves just as they pulled up into her drive way.

"What happened in the kitchen, Blaine?" She blurted, a blush creeping onto her cheeks.

Blaine sighed heavily and looked over at Kate. "You're like a daughter to me, Kate, that's what happened."

You could practically hear the sound of Kate's heart breaking at what he just said. "Oh," She murmured, opening the car door. "I- Um, I'll see you Sunday morning for breakfast." And with that she had gotten out of the car and slammed it before even letting Blaine get a word in.

Blaine said as he watched the young girl, _very young girl_ , storm up the driveway and into her home.

* * *

Kate didn't understand why she was getting so upset over something so little. She should think of Mister Anderson, Blaine, that way herself. He has practically raised her all her life, just as if Blaine was like a second father to her.

"Katie bug," Kate heard her dad call her, sounding as if he was in the kitchen. "Dinner is almost done, come help Finn set the table." She sighed and kicked off her converses and headed into the kitchen.

"I'm sorry for almost being late, Dad." She smiled at Burt softly. "I promise it won't happen again, Rachel and I just practically fell asleep on her couch watching movies."

"Does Rachel like me, or something?" Finn suddenly said, "Because she's always staring at me, which is flattering I guess."

Kate couldn't help but roll her eyes. "Finn, sweetie, your conceded attitude is showing." She indicated, setting up the table as she did. "I think you should talk to her though, Rachel is a very sweet girl."  
 _  
_Finn smiled his half smile, nodding. "Puck knocked up my last girlfriend and I'm just afraid he'll do that again."

"Finn, stop being dumb," Kate suggested with a laugh. "Quinn help cheat along with Noah, okay? Rachel is not that kind of girl let along person."

"Let's sit down and chow down on this roast that Burt and I made for us." Carole suggested, setting the food down on the dining room table.

As soon as Friday night dinner was over Kate excused herself from the table and headed down to the basement where her room was currently located. Her normal routine was done as usual, showering, face ritual, and reading part of the book she is currently reading.

Kate grabbed her phone from the night stand and wrote out a text before sending it to Rachel.

 _Got home safe, almost done with_ Fifty Shades of Grey _, it's rather interesting. About to head to bed, goodnight, love you lots._

The next text she got from her best friend which was about ten minutes later.

 **Love you too, night.**

* * *

Sunday morning rolled around, Blaine woke up at eight o'clock sharp as per usual for these mornings. What was not usual was that night he had a really intense dream about Kate. It was the not the first one he's had either.

The dream's he's been having has been happening more frequently, Rachel even came into his room one night just because of the moans he was making.

He got up out of bed and went into the bathroom to turn on the steaming hot shower before getting into it. Blaine's mind went straight to the thought of Kate. Sweet, innocent Kate. He grabbed his half flaccid cock with the palm of his hand before starting to stroke it lazily.

Just the thought of Kate drove Blaine crazy. He could just imagine taking Kate into his office and fucking her until her legs were numb and her ass was perfect shade of red. "Fuck." Blaine grunted, his chest starting to heave. Hearing Kate's little breathless moans must be glorious, or seeing the way she touched her soaking pussy. Her cheeks blushing furiously as if she had just been walked in on, especially if Blaine was the one.

Blaine could feel the build up in the bottom of his stomach before he finally exploded, coming furiously into his hand. "Shit, shit, shit." He exclaimed heavily, jerking forward. "Kate." Slipped his mouth as he finished, breathing loudly.

Okay maybe he shouldn't have just jerked off to the thought of his daughter's best friend, especially in vulgar ways but Blaine couldn't help it. Kate Hummel was an extraordinary sculpture, purely perfect in his eyes.

He finished up in the shower, washing his hair and body before getting out. Blaine dressed in a simple grey cardigan from _Barneys_ along with pants that he had gotten from the latest Marc Jacobs collection. He added his signature look with a blue Bowtie that Kate had gotten last Christmas.

"Kate! You'll never guess what happened last night!" Rachel exclaimed in excitement.

Blaine could vaguely hear the conversation between them, not letting the butterflies in his stomach take over. He made his way down the stairs, interrupting the conversation. "Good morning, ladies." He grinned. "What happened last night, Rachel?"

"Finn texted me, dad! He actually texted me," Rachel basically beamed with happiness. "He's the most popular boy in school."

"And also, my step brother, Rach." Kate laughed and shook her head. "You could've came over and just talked to him, he would've talked back."

"I agree with Kate, not that I'm condoning you talking to boys just yet." Blaine sneered in a joking way. "I still see you as my two year old baby playing with her Barbie dolls, and that's including you Kate."

Rachel rolled her eyes before cackling. "Oh come on, dad. We're seventeen years old, we're aloud to talk to boy." She smiled. "And what about you? When's the last time you had a date?"

Blaine practically choked on his coffee, staring at his daughter. "About… Three years ago." He couldn't help but mutter. "And that didn't work out because you know that lady was crazy."

Kate kept herself quiet as she ate the breakfast that had just been prepared for all of them. Just thinking of Blaine with another girl made her wince. These feelings that she had just recently developed for Blaine, for Rachel's _father_ , had gotten stronger than they were before.

Sure she had a crush on him when her and Rachel were younger but this was different. Kate was practically an adult now and Blaine was still the same as were her feelings for him.

"What do you think, Katie? Don't you think that he needs to get back into the dating game?" Rachel suggested, looking over at Blaine. "I don't want you to die alone."

"Thanks Rachel, what a loving daughter you are." Blaine deadpanned, rolling his eyes. Even though she wasn't wrong, he didn't know if dating was such a good idea. He looked over at Kate and nearly groaned before catching it himself. Maybe it was, just to somehow get Kate off his mind.

"I- I guess." Kate mumbled out, swallowing a mouth full of pancakes as she cleared her throat. "It's really none of my business, Rachel. Leave your dad alone."

The icy cold glare Rachel just gave her was beyond her normal bitch face. "Anyways, Finn asked to come over today so I can help him study for his Spanish test."

Kate raised an eyebrow before humming. "I thought you we were going to the new store that just opened in the mall today?" She acted a bit annoyed but was quite relieved, maybe this is her chance to actually talk with Blaine.

"Oh come on, Katie. We can go there any time," Rachel nudged her best friend with a smile before whispering. "This is my chance to actually spend time with Finn! You should understand."

"I heard that." Blaine grumbled, turning the page of news paper.

Kate understood completely because this is exactly what she wanted to do with Blaine. "I guess you're right," She spoke, standing up from her seat. "Do you need help with anything today, Mister Anderson? I can stay back, I mean, if you want me too."

Did Blaine just hear her right? "Well today is Sunday, I was going to finish painting the upstairs bedroom," Blaine suggested. "And since Rachel is bailing, maybe you could help me?"

"I'd love to help." Kate replied, completely ecstatic.

Rachel looked at both of them, eating the last bite of her food. "I guess I'll see later back at your house then, Kate." With that, Rachel had gotten up and left the room, leaving them completely alone. Together.

 _Maybe this isn't such a good idea,_ Blaine thought to himself. "Well, then let's get to it then, shall we?" He grinned and led Kate up stairs to the empty guest bedroom that was half painted a lovely yellow color. "I hope you're wearing clothes that can get messy." He went to the radio that was on the ground and pressed play.

Kate looked down at her outfit, silently thanking herself for wearing not too expensive of clothing. All she had on was just a simple pair of jeans that fit her all in the right ways, along with a white tank top and high tops.

She grabbed a paint brush from the ground and dipped into the paint before spreading it across the wall, humming along with the song that had just popped on the radio, which was _Slave 4 u_ by Britney Spears.

Kate let her hips sway to the music in an exotic way, singing along. "…I'm slave for you, I cannot hold it, I cannot control it." The music flowed through her body in the most amazing way, completely forgetting that Blaine was there.

Blaine almost dropped his paint brush at the inappropriate moves that Kate was dancing, her sing song voice going perfectly with each sway. He was completely mesmerized. It took all that was in Blaine not to reach out and grab Kate's perfectly shaped ass.

The song finally ended, _thank god,_ Blaine thought to himself and cleared his throat. "Make sure not to leave any brush stroke marks on the wall, Kate."

Kate jumped at the sound of Blaine's voice, nearly squeaking. "Oh, yes, I know." She smiled weakly over at him, blushing uncontrollably.

"Good girl." Blaine nudged her with a grin, painting along the same wall as her before accidentally getting paint on Kate's hand.

She gasped, looking down at her hand before laughing. "It's game on, Mister Anderson." She reached her paint brush over to Blaine's shirt and ran it across swiftly.

Blaine looked at Kate in a disbelieving way, before smirking. "Oh it's on." They chased each other around the room, every other second one of them painting on each other, their clothes and their skin. Kate ended up slipping on the sheet that was on the ground and fell right into the buckets of paint.

"Oh god, shit. Kate." Blaine exclaimed, reaching down for her hand. "Are you okay?"

Kate rolled her eyes and took Blaine's hand, smirking. "Mister Anderson, calm down," She mumbled, finally pulling Blaine's hand and down to the ground with her. The look of pure horror on Blaine's face made her burst out into a fit of giggles.

"You think this is funny, huh?" Blaine grabbed Kate and pulled her over to him, letting his fingers creep onto her hips before starting to tickle them. "This is what you get!"

"S-S-Stop!" Kate piped out, her body squirming. Her laughs filled the room with a beautiful tone that Blaine absolutely fell in love with.

"What's that? You want me to stop?" Blaine grinned, his hands moving up and down her body. "Beg, Kate Elizabeth."

"P-Pl-Please, Please, st-stop!" She shouted, finally taking a breath as she felt Blaine stop his fingers. "That was not fair, you cheated!" Kate stuck her tongue out before letting out a small giggle, pushing up her glasses. "You know my weakness."

Blaine beamed and looked down at Kate softly, sighing. "You're really adorable, you know that?" He murmured out, caressing Kate's face in an endearing way.

Kate then made their lips collide together in a perfect sync , letting her eyes flutter shut. "Mmm.." She hummed.

Blaine couldn't really say he was surprised that she was going to be the brave one and kiss him. After a moment he let himself kiss Kate back just as gently, rubbing her cheek with his thumb as they pulled away.

"Woah." Kate whispered, her eyes flickering up to Blaine's as she pushed her glasses back up. "That was- Woah."

Blaine smiled down at her, her innocence was one of the most adorable things about Kate. Then it hit him. He had just let Kate kiss him. His daughters best friend. It may have felt amazing but it was so, so wrong. "A mistake."

"What?" Kate's head snapped, her eyes staring into Blaine's.

"It was a mistake." Blaine mumbled, standing up from the ground. "I think you should leave, Kate."

Kate didn't understand what was happening. The first minute they were running around the room playing with each other, then the next they were on the ground kissing and now Blaine was saying it was a mistake.

"You can't deny the chemistry we have between us, Blaine." Kate whispered brokenly. She knew that he knew there was something between them.

"You need to leave, Kate Elizabeth. Now." Blaine snapped, his eyes avoiding Kate completely. "I knew I shouldn't have let you help me."

Kate gave him her most epic bitch glare. "Fine, I'll leave," She bit her lip. "Text me when you know I'm right." She then stormed out of the room in a complete rage

Blaine sighed heavily before cleaning up the mess that they had just made before grabbing his phone and dialed Sam's number.

"Hello?" Sam said from the other end of the line.

"Same. I'm fucked. I'm so fucked up." Blaine groaned into the phone.

"Blaine, slow down. Tell me what happened?" Sam encouraged. "Sit down, take a drink of water and explain to me."

Blaine sighed heavily. "We kissed."

"Who did you kiss?"

"Kate and I kissed," Blaine mumbled. "I can't believe I actually let myself kiss my seventeen year old daughters best friend."

Sam gasped and tried to register what he had just heard. "Wait, wait, wait." He said. "You kissed Kate? Kate Hummel?"

"Are you deaf or something? That's what I just said." Blaine huffed. "What the hell am I going to do, Sammy?"

"You may have kissed someone who is underage but in the state of Ohio, the legal age of consent is sixteen, and it's not like you had sex with her."

Blaine sighed once more. Sam was right, it's not like he was Kate's teacher or something. It was perfectly legal for them to have kissed, had sex even. But in the eyes of the public, it was very wrong for that large of an age gap to be together.

"You're right, Sam." He muttered over the phone. "But she's seventeen, and I'm thirty five." Blaine then face palmed himself. "She's the same age as Rachel, I could practically be her father."

Sam rolled his eyes and laughed. "Blaine, I'm not condoning this in anyway but if this is what is going to make you happy, then I say go for it. Listen to your heart."

"You're such a sap, Evans." Blaine cackled weakly. Maybe Sam was right again, even though society didn't agree with it doesn't mean he can't be happy. Sure they'll have to hide it until Kate turns eighteen but that didn't bother Blaine, and he hoped it wouldn't bother Kate.

"I've have to go, Sam."

"Call me later." Sam said, hanging up.

Blaine typed out a text on his phone.

 _Meet me in the Lima Bean after you get out of school tomorrow. We need to talk.  
xoxo B_

Kate's reddened eyes filtered over the text that she had just received carefully before smiling weakly. She hadn't known for sure when she was going to get a text from Blaine but she was ecstatic to have received it sooner rather then later.

 **I can't wait, see you then.  
xx K  
**


End file.
